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<div class="ref_head">&nbsp;UDT Reference: Functions</div>

<h4 class="func_name"><strong>accept</strong></h4>
<p>The <b>accept</b> method retrieves an incoming connection.</p>

<div class="code">UDTSOCKET accept(<br />
&nbsp; UDTSOCKET <font color="#FFFFFF">u</font>,<br />
&nbsp; struct sockaddr* <font color="#FFFFFF">addr</font>,<br />
&nbsp; int* <font color="#FFFFFF">addrlen</font><br />
);</div>

<h5>Parameters</h5>
<dl>
  <dt><i>u</i></dt>
  <dd>[in] Descriptor identifying a listening socket.</dd>
  <dt><em>addr</em></dt>
  <dd>[out] Address of the peer side of the new accepted connection.</dd>
  <dt><em>addrlen</em></dt>
  <dd>[out] Length of the <i>addr</i> structure.</dd>
</dl>

<h5>Return Value</h5>
<p>If no error occurs, <b>accept</b> returns the UDT socket descriptor of the new connection; otherwise, it returns
  UDT::INVALID_SOCK.</p>
<p>On a successful return, the address of the peer 
  side of the connection is written into <i>addr</i>, and its length is in <i>addrlen</i>, if the <i>addr</i> parameter is not NULL.</p>
<p>If an error is returned, the error information 
  can be retrieved by <a href="error.htm">getlasterror</a>. One of the following error can cause an <b>accept</b> error:</p>

<table width="100%" border="1" cellpadding="2" cellspacing="0" bordercolor="#CCCCCC">
  <tr>
    <td width="17%" class="table_headline"><strong>Error Name</strong></td>
    <td width="17%" class="table_headline"><strong>Error Code</strong></td>
    <td width="83%" class="table_headline"><strong>Comment</strong></td>
  </tr>
  <tr>
    <td>EINVSOCK</td>
    <td>5004</td>
    <td><i>u</i> is an invalid UDT socket.</td>
  </tr>
  <tr>
    <td>ENOLISTEN</td>
    <td>5006</td>
    <td><i>u</i> is not in the listening state.</td>
  </tr>
  <tr>
    <td>ERDVNOSERV</td>
    <td>5007</td>
    <td><i>u</i> is set up to support rendezvous connection.</td>
  </tr>
  <tr>
    <td>EASYNCRCV</td>
    <td>6002</td>
    <td><i>u</i> is non-blocking (UDT_RCVSYN = false) but there is no connection available.</td>
  </tr>
</table>

<h5>Description</h5>
<p>Once a UDT socket is in listening state, it accepts new connections and maintains the pending connections in a queue. An <strong>accept</strong> call retrieves 
the first connection in the queue, removes it from the queue, and returns the associate socket descriptor. </p>
<p>If there is no connections in the queue when <strong>accept</strong> is called, a blocking socket will wait until a new connection is set up, whereas a 
non-blocking socket will return immediately with an error.</p>
<p>The accepted sockets will inherit all proper attributes from the listening socket.</p>

<h5>See Also</h5>
<p><strong><a href="listen.htm">listen</a>, <a href="connect.htm">connect</a>, <a href="opt.htm">setsockopt</a>, <a href="opt.htm">getsockopt</a></strong></p>
<p>&nbsp;</p>

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